Polyphenylene ether resins and compositions having reduced odor and method of reducing odor in same

Abstract

The odor of blends of polyphenylene ether resin, alone, or in combination with a polystyrene resin or a high impact polystyrene is improved by including a carboxylic acid, an acid anhydride or mixture thereof in the compositions.

I claim: 
     
       1. A thermoplastic composition comprising (a) a polyphenylene ether resin, in combination with a polystyrene resin; and   (b) a carboxylic acid, in an amount to effectively reduce the odor of (a).   
     
     
       2. The composition of claim 1, in which component (a) is comprised of a polyphenylene ether in an amount from about 10 to about 90 parts by weight and a polystyrene resin in an amount from about 90 to about 10 parts by weight, based on 100 parts by weight of (a). 
     
     
       3. The composition of claim 2, in which component (a) is comprised of a polyphenylene ether in an amount of about 50 parts by weight and a polystyrene resin in an amount of about 50 parts by weight. 
     
     
       4. The composition of claim 1, in which the polyphenylene ether is a homopolymer or copolymer containing structural units of the formula ##STR6## in which for each of these units independently each Q 1  is hydrogen, halogen, primary or secondary lower alkyl having up to seven carbon atoms, phenyl, haloalkyl or aminoalkyl wherein at least two carbon atoms separate the halogen or nitrogen atom from the benzene ring, hydrocarbonoxy, or halohydrocarbonoxy wherein at least two carbon atoms separate the halogen and oxygen atoms; and each Q 2  is independently hydrogen, halogen, primary or secondary lower alkyl, phenyl, haloalkyl, hydrocarbonoxy or halohydrocarbonoxy as defined for Q 1 . 
     
     
       5. The composition of claim 1, in which the polyphenylene ether is poly(2,6-dimethyl-1,4-phenylene ether). 
     
     
       6. The composition of claim 5, in which the poly(2,6-dimethyl-1,4-phenylene ether) has an intrinsic viscosity of about 0.30 to 0.6 deciliters per gram in choroform at 25° C. 
     
     
       7. The composition of claim 1, in which the polyphenylene ether is poly(2,6-dimethyl-co-2,3,6-trimethyl,1,4-phenylene ether). 
     
     
       8. The composition of claim 1, in which component (b) is present in an amount of from about 0.1 to about 10 parts by weight, based upon 100 parts by weight of (a). 
     
     
       9. The composition of claim 1, in which component (b) is present in an amount of from about 0.1 to about 1.0 parts by weight, based upon 100 parts by weight of (a). 
     
     
       10. The composition of claim 3, in which component (b) is present in an amount of up to about 1.0 parts by weight, based upon 100 parts by weight of (a). 
     
     
       11. The composition of claim 1, in which component (b) is selected from carboxylic acids having the general formula X--COOH where X is selected from hydrogen; methyl; alkyl, CH 3  (CH 2 ) n , where n is a whole number and is at least equal to 1 and is preferably 2 to 16; aryl; branched cyclic or substituted alkyl; branched cyclic or substituted alkenyl; substituted aryl; or mixtures of the foregoing. 
     
     
       12. The composition of claim 1, in which component (b) is selected from dicarboxylic acids having the general formula HOOC--X--COOH where X is a sigma bond or is a difunctional radical selected from straight or branched alkyl radicals, straight or branched alkenyl radicals, aryl radicals, or substituted radicals of any of the foregoing. 
     
     
       13. The composition of claim 12, in which component (b) is selected from oxalic acid; malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, bromoglutaric acid, and dimethylglutaric acid or mixtures of the foregoing. 
     
     
       14. The composition of claim 1, in which component (b) is a tricarboxylic acid. 
     
     
       15. The composition of claim 14, in which component (b) is citric acid. 
     
     
       16. An article molded from the composition of claim 1. 
     
     
       17. A method of reducing the odor in a composition comprised of (a) a polyphenylene ether resin, in combination with a polystyrene resin, said method comprising adding (b) a carboxylic acid, to (a) in an amount sufficient to reduce the odor of (a). 
     
     
       18. A thermoplastic composition comprising: (a) a polyphenylene ether resin, in combination with a polystyrene resin; and   (b) at least 0.1 parts by weight, based upon 100 parts by weight of (a) of a carboxylic acid.   
     
     
       19. A method of reducing the odor in a composition comprised of (a) a polyphenylene ether resin, in combination with a polystyrene resin, said method comprising adding (b) at least 0.1 parts by weight, based upon 100 parts by weight of (a) of a carboxylic acid, to (a).